The prior art related to equipment for feeding infants includes a range of devices which usually include a flexible nursing nipple which is mounted in the removable cap of a bottle. The cap and the bottle typically form a threaded closure.
One of the disadvantages of the apparatus according to the prior art is related to the use of the apparatus in the feeding of infants with regard to the use of breast milk and/or baby formula. When bottle feeding an infant using breast milk or formula, the infant oftentimes does not drink all the milk. Because both breast milk and infant formula have significant value, it would be desirable to be able to store the partially used bottle. However, the storage of a partially used bottle is objectionable because bacteria present in the infant's saliva may ooze through the nipple into the milk remaining in the bottle. This increases the rate of spoilage of the remaining milk.
This problem of spoilage is especially troublesome when feeding infants who take only small amounts of milk at each feeding thereby extending the periods during which the conventional partially filled nursing bottle must be stored.